XIX 



141a. Flowers in catkins, without brightly colored or petal-like parts 



142. 

 141b. Flowers not in catkins, either with or without brightly colored 



or petal-like parts 149. 



142a. Leaves 2-ranked, as shown by the arrangement of buds 

 and leaf-scars in two longitudinal rows, so that the third bud 

 is directly over the first 143. 



142b. Leaves and leaf-scars not 2-ranked 146. 



143a. Bundle-scars three in each leaf-scar 144. 

 143b. Bundle-scars several in each leaf-scar 



2b, in URTICACEAE, p. 23. 



144a. Leaf-buds with only 1 3 visible bud-scales 



10, in BETULACEAE, p. 22. 



144b. Leaf-buds with more than 3 visible scales 145. 



145a. Bark of the branches smooth and dark gray, the larger stems 

 fluted with projecting longitudinal ridges 



Ib, in BETULACEAE, p. 21. 

 145b. Branches without projecting ridges 4, in BETULACEAE, p. 22. 



146a. Pith 3-angled 8, in BETULACEAE, p. 22. 



146b. Pith 5-angled 13b, in FAGACEAE, p. 23. 



146c. Pith cylindrical 147. 



147a. Visible outer bud-scales 2 or more 148. 

 147b. Buds with a single visible outer scale 



13, in SALICACEAE, p. 20. 



148a. Bundle-scars 3 in each leaf-scar MTEICACEAE, p. 20. 



148b. Bundle-scars more than 3 in each leaf-scar 



2b, in URTICACEAE, p. 23. 



149a. Flowers dark red-purple, about 3 cm. wide 



ANONACEAE, p. 40. 

 149b. Flowers bright pink, irregular, about 1 cm. wide 



3a, in LEGUMINOSAE, p. 58. 



149c. Flowers white, with 5 conspicuous petals 150. 

 149d. Flowers greenish or yellowish, small, inconspicuous 152. 



150a. Ovary 1, superior, i. e., in the center of the flower and not 

 attached to surrounding parts 36, in KOSACEAE, p. 54. 



150b. Ovary inferior, appearing as a swelling below the calyx 

 at the apex of the pedicel 151. 



151a. Flowers in racemes or solitary 42b, in ROSACEAE, p. 55. 

 151b. Flowers in flattened or rounded branching clusters 



42a, in KOSACEAE, p. 55. 



152a. Stems thorny la, in EUTACEAE, p. 65. 



152b. Stems not thorny 153. 



